Magnetic device



July 24, 1962 K. D. BROADBENT 3,046,532

' MAGNET DEVICE Original Filed Aug. 2, 1957 3 Sheets-Sheet l PRIME '0 OUTPUT Kent D. Broodben'r, INVENTOR.

1 1 Y I Ill ATTORNEY.

July 24, 19 2 K. D. BROADBENT MAGNET DEVICE 1 Original Filed Aug. 2, 1957 3 Sheets-Sheet 2 PRIME" ll ONE" Kent D. Broadbeni,

INVENTOR.

Mme 9 ,5;

ATTORNEY.

July 24, 1962 K. D. BROADBENT 3,046,532

MAGNET DEVICE 3 Sheets-Sheet 3 Original Filed Aug. 2, 1957 PRIME v F /g. 7.

5 i II "5!) Q BUCKING I PORTION I 1 WRITE GEN. 20

I I I2 l PRIME DRIVE 9 "NOT" IO 8 ago l 20 GEN. wnm-z l:

GEN |6 I22 I I2 I I4 DRIVE F g. 6

INPUT INFORM- ATION Kent D. Broodben'r,

//v VENTOR.

9 Unit Stts 3,046,532, 7 MAGNETIC DEVICE Kent D. Broadbent, San Pedro, Calif., assignor to Hughes Aircraft Company, Culver City, Calif., a corporation of Delaware Original application Aug. 2, 1957, Ser. No. 675,918. Di-

vided and this appgilication July 28, "1958, Ser. No. 751,383

7 Claims. (Cl. 240-474 This invention relates to magnetic devices and more particularly to multipath magnetic elements capable of use as controlling and computing elements and the like and to systems including such magnetic elements.

This application is a divisional application of the earlier filed application Of KJD. Broadbent, Serial No. 675,918, now Pat. No. 2,993,197, filed on August 2, 1957, and entitled Magnetic Device, and assigned to the same as-' signee as this application. 7

.Magnetic devices-employing magnetic cores having a substanially square hysteresis characteristic have been utilized to a large extent as switching, controlling and computing elements. In all of these applications, toroidal or ring-shaped cores, which have single apertures and unique flux paths, have been used because of their bistable properties. Experimental work on this basic type of magnetic core device has led to the development of novel devices vice and which control is not possible with the aforementioned toroidal type cores.

Magnetic shift registers have been developed employing the conventional unique flux path magnetic structures. These conventional magnetic shift registers, however, require unilateral impedance devices, such as diodes, in their transfer loops to maintain the forward flow of information without any back flow thereof. The diode is known to be the most expensive and least reliable element in a magnetic shift register. Therefore, a shift register arrangement eliminating diodes, yet being capableof operating at high speeds, is in much-demand. The aforementioned development of multipath magnetic structures has accelerated this search for diodeless magnetic shift registers.

.Accordingly, it is desirous to provide a multipathmagnetic structurethat is capable of use as a control or computer element including shift register operation without resorting to the use of unilateral impedance elements.

It is, therefore, a general object of this invention to provide a novel and improved magnetic, element capable of use as a controllingor computing element. I

It is another object of this invention to provide a novel and improved magnetic device capable of being employed as a magnetic shift register element, a gating element, or a flip-flop element. A g

It is still another object of this invention to provide a novel and improved magnetic shift register, without resorting to the use of unilateral impedance devices, that is more reliable, yet less expensive to construct than prior art devices. p

It is a further object of this invention to provide a novel and improved high speed, completely magnetic, integral shift register of the character of the aforementioned ob- 3,646,532 Patented July 24, 1 962 its the forward flow to one storage element.

'Further and additional objects and advantagesfwill become apparent hereinafter during the detailed description of the embodiments of the invention which are to follow and, which, are illustrated in the accompanying'drawings wherein: 1

PEG. 1 is a schematic representation of a novel magnetic element embodying the invention;

FIG. 2'is a representation of typical geometrical configurationand the relative dimensions of the novel magnetic element of FIG. 1; p

FIG. 3 is a representation of various flux configurations present in the multiple paths of the novel magnetic element shown in FIG. 1 during the variousstable conditions thereof;

FIG. 4 is a schematic representation of a flip ilop circuit employing the novel magnetic element of FIG. 1;

FIG. 5 is a graphic representation of typical wave forms derived from the flip-flop circuit of FIG. 4;

FIG. 6 is a schematic representation of a magnetic shift register arrangement employing the magnetic element of FIG. 1;

FIG. 7 is a schematic representation of a modified mag netic element;

FIG. 8 is a schematic representation of a logical for circuit arrangement; and

FIG. 9 is a schematic representation of a logical not circuit. I

' Generally, theinvention contemplates the provision of a novel multiple aperture magnetic'element having a predetermined geometric configuration so as to define stable multiple flux paths therein. The apertures are interlaced with windings so as to be magnetically coupled in a novel manner to cause the flux generated in the magneticstructure to assume a plurality of essentially closed magnetic configurations. These assumed configurations are stable magnetic conditions within the magnetic element and which conditions are controlled in a unique manner, to not only store binary coded information but also toallow the binary information to be readily transferred therefrom, so as to becapable of providing a controlled unilateral transfer. 1

Now referring to the drawings, the basic arrangement of a novel magnetic element 10 will be described inconjunction with the magnetic element shown in FIG. 1. The magnetic material employed for the magnetic element 10 preferably has a substantially square or rectangular hysteresis characteristic. 1 The magnetic material may be in the form of'a conventional 'toroid or ring, as illustrated in FIG. 1, or may be a thin magnetic film. The-latter magnetic form and the preparation thereof 'is well known in the art asevidenced bythe publication of M. S. Blois, Jr., entitled Preparation ,of-Thin Magnetic {Film and their Properties appearing in the Journal of Applied Physics for August 1955, on pages 975 through 980 published by the American Institute of Physics, 57 East- 55th Street, New York, New York. a

.A preferable geometric configuration for thernagnetic element 10 and the relative dimensions therefor is shown in FIG. 2. The element 10 is shown with a pair of spaced apart circular apertures 12 and 14 having respective diameters on the order of 6:1. The center of the aperture 12 is positioned so that the outer peripheral edge thereof is spaced inwardly from a tangent line to the left-hand edge of the element 10, a distance generally denoted as 2a. Also, tangent lines to the top and bottom edges of the element 10 are spaced a distance approximately 2a from the respective edges of the aperture 12. 'The'right-hand peripheral edge of the aperture 12 is spaced inwardly t a tween the apertures 12 and 14 is shown as a with the aperture 14 being spaced inwardly from a tangent line to the right-hand edge of the magnetic element It), a similar distance a. The same relative dimensions for the apertures 12 and 14 hold for the magnetic element whether the element is in the form of a toroidal core or in terms of a magnetic film.

The multiple flux paths resulting from the aforementioned geometric configuration may be better appreciated by considering the flux paths as passing through discrete legs in the element 10 defined by the apertures 12 and 14. A leg 1 is considered to be defined by the area extending inwardly from the outer peripheral edge, or the left-hand edge of the magnetic element 10 to substantially the center of the distance between this left-hand edge and the adjacent peripheral edge of the aperture 12; see FIG. 3. A leg 1 is similarly defined by the area extending from the right-hand extremity of leg 1 to the peripheral edge of the aperture 12. Magnetic legs are similarly defined by the area between the apertures 12 and 14 and which leg is identified as leg 2 in FIG. 3 while the area between the outer peripheral edge of aperture 14 and the right hand edge of the magnetic element 10 is denoted as leg 3. An input winding 16 for the magnetic element 10 is magnetically coupled to the magnetic element It] for con trolling the magnetic condition or state of leg 2. The input winding 16 is magnetically coupled to the element 10 by being interlaced through the aperture 14, as shown in FIG. 1, so as to only control leg 2; that is, the coercive force produced by the energization of winding 16 is effective only in leg 2. A prime winding 18 is also magnetically coupled to the element 10 by means of aperture14 and is oriented thereon so as to control only the magnetic condition of leg 3. The remaining winding coupled to the magnetic element 10 by being interlaced through the aperture 14 is denoted as the output winding 20. The output winding 20 is interlaced through the aperture 14 so as to have a voltage gene-rated therein only upon a change of flux in leg 3.- The remaining winding magnetically coupled to the magnetic element 10 is identified as drive winding 22. Drive winding 22 is interlaced through aperture 12 and arranged thereon to control the magnetic condition of legs 1 and 1'. It should be recognized at this point, and will be appreciated more fully from the description to follow, that this drive winding 22 controls legs 1 and 1 to act as both a transfer out and a blocking function. The blocking function of winding 22 does awaywith the need for a separate block winding to ly for purposes of more clearly explaining the invention,

the various stable states will be identified in terms of the well known binary notation as the magnetic-element It) would be employed in a digital computer. Accordingly,

the stable states are shown and identified in FIG. 3, reading from left to right, as the zero, the one, and

the prime states. The zero state is considered as the initial magnetic state of the element 10 for the purpose of explaining this invention. The flux patterns defining the zero state is such that the magnetic element 10is magnetized toroidally around aperture 12; that'is, a closed flux path is formed by flux linking leg 1 and leg 3 and a second closed path linking leg 1 and leg 2. The one state is assumed by the magnetic element 10 when the input winding 16 is provided with a current for producing a coercing field, H, in leg 2 acting in a counter-clockwise direction or to reverse the direction of flux in leg 2 from that of the zero state. Upon the application and termination of such an energizing current to the winding 16, the flux around aperture 12 linking leg 1 and leg 2 will be reversed, that is, will travel counter-clockwise. The

4 flux linking through leg 1 and leg 3 is left in its original clockwise orientation.

The prime state is effected by energizing prime winding 18 to produce a coercive force in leg 3 to reverse the direction of the flux in legs 2 and 3. The reversal of the flux in legs 2 and 3 is considered to cause the flux in these two legs to close toroidally about aperture 14. The flux in legs 1 and 1* will at this same time assume a crescent-shaped configuration as shown in FIG. 3 in going from the one state to the prime state. It is considered that the crescent-shaped configuration is the only closed configuration consistent with the polarity of the coercing force and the magnitude of the prime current that was employed in the operation of the element 10. The magnetic element 10 will not assume the other configuration possible at this interval since it would require a high priming current to effect such a change. This possible configuration would saturate the element 10 in a counterclockwise direction about aperture 12 or merely change the direction of flux through legs 1 and 3.

Now referring to P16. 4, a bistable circuit 23 employing the novel magnetic element 10 will be described with the aforementioned flux configurations in mind. The

bistable circuit 23 employs a pair of the novel magnetic elements identified by the reference characters 24 and 26. The magnetic element 24 has an aperture 28 and an aperture 30 for receiving the windings interlaced to the element 24 while the corresponding apertures for the element 26 are identified as apertures 32 and 34. The magnetic elements 24 and% are arranged with the same windings as described hereinabove but in a novelmanner .to define an all magnetic, dynamic" flip-flop circuit.

The term dynamic is used in the sense that a binary bit of information is continually shifted back and forth between the elements 24 and 26 and which binary bit may be changed in accordance with the input information delivered to'the bistable circuit 23. The binary bit of information shifted between the elements 24 and 26 is continually read-out to thereby give an indication of the storage condition of the bistable circuit 23. The input information delivered to the bistable circuit 23, in this instance, is derived from the computer proper and delivered to a pair of input windings 36-and' 38 coupled to the element 24. The windings 36 and 38 are further identified as the one and zero input windings, respectively, in accordance with conventional terminology.

The winding 36 is magnetically coupled to the element 24 by being interlaced through the aperture 30 to control the flux in leg 2. The input winding 38 is also interlaced through the aperture 30 to control the flux in leg 2 but is magnetically oriented with respect to the winding 36'so as to produce a coercive force in leg 2 acting in the opposite direction from that produced by the winding 36. A prime winding 40 is interlaced through aperture 30 to control leg 3 and is connected to a prime source 42, shown in block form. A drive winding 44 is also interlaced through aperture 28 to magnetically coerce legs 1 and 1 and is similarly energized through a' drive source 46'also shown in block form. The output signal from the magnetic element 24 is derived therefrom by means of the output winding 48 interlaced through aperture 32 so as to be linked by the flux changes in leg 3. The output winding 48 is connected in a series circuit relationship with an input winding 50 interlaced through the aperture 34 for magnetic element 26 to form a transfer circuit. The transfer circuit comprising windings 48 and 50 may include a series resistor 52 therein to reduce the time constant of the transfer circuit.

The input winding 50 for the element 26 is magnetically coupled thereto to control the flux in leg 2. The magnetic element 26 is also provided with a prime winding 54 interlaced through aperture 34 for controlling leg 3 and with a drive winding 56 interlaced through aperture 32 to control legs 1 and 1 The winding 54 is connected through a prime source 58 while'the drive winding 56 is similarly connected to a drive source 60. An output winding 62 is magnetically arranged with the apenture 34 and leg 3 of the element 26 to provide an output signal from the element 26 and which output signal is transferred to the element 24 by means of a transfer loop including a winding 64 interlaced through the aperture 39 for controlling leg 2 of element 24. The relative orientation of winding 64 is the same as that'for input winding 36, the one winding. Accordingly, it will be appreciated that the coercive forces produced by winding 64 and the zero winding 38 are in opposite directions. A read-out winding 65 is also interlaced through the aperture 34 to be responsive to the flux changes in leg 3 of element 26 and thereby provides the dynamic signal representative of the binary state of the bistable circuit 23.

Assuming that the elements 24 and 26 are both in the zero-state, the operation of the bistable circuit 23 will be described. With both the elements 24 and 26 in this zero magnetic condition and the one input winding 36 energized, the element 24 will assume the one state shown in FIG. 3. Accordingly, upon a pulse being delivered from the priming source 42 to the prime winding 40 of element 24, the latter will now assume the prime condition, that is, the crescent-shaped pattern will exist. After the magnetic element 24 assumes the primed state, the current from drive source 46 is applied to drive winding 44 to cause the element 24 to switch from the prime state back to the zero state and during which interval an output signal will be generated in the output winding 48.- This output signal is representative of the binary bit of information that was previously delivered to the magnetic element 24, (the one) by means of input winding 30. This same bit of binary information is transferred into the windingStl for storage in magnetic element'26.

The sequencing for the magnetic element 26 is similar to that for the element 24, that is, first the prime winding 54 is energized followed by the energization of the drive 'winding 56. Following the energization of the drive winding 56, the one is transferred back into element 24- by means of the output winding 62 of the element 26 and the winding 64 of the element 24. Simultaneously with this transfer of binary bits between the elements 26 and 24, a voltage is generated in read-out winding 65, representative of the one, substantially as shown in FIG. 5. This same bit of binary information will be transferred back and forth between these elements as long as neither input winding 36 or 38 is energized or a one is delivered to winding 36. If the input information delivered to the bistable circuit 22 calls for a change of this information, namely a zero; the zero input winding 38 will be energized. Accordingly, the timing of the transfer of the binary bit from the element 26 to the element 24 is arranged so that'the input information coupled to the input winding 38 arrives at substantially the same time as the binary bit transferred to the winding 64. Since the windings 38 and 64 produce coercive forces in leg 2 in opposite directions, the bit from element 26 will not be stored in the element 24 and the latter element is left in its zero state. ergization of the priming winding 40 and the drive winding 44 for the element 24 a zero" signal will be delivered to element 26. The transfer of this zero signal into the element 26 will not effect its zero state. Upon the successive energization of priming winding 54 and drive winding 56, the zero will be once again stored in the element 24. At this same time the zero read-out signal substantially as shown in FIG. 5 may be derived from the read-out winding 65.

When a zero is read into the magnetic element 24, it will be recalled from the above discussion that the binary one transferred from magnetic element 26 to the magnetic element 26 to the magnetic element 24 is not written ino the latter element and accordingly the magnetic element 24 remains in its zero state. When the magnetic element 24 is in its zero state and the prime winding 40 Therefore, upon the successive enis energized, the coercive force set up by'the prime winding 46 attempts to reverse the direction of the flux in leg 3. In order to effect this reversal of flux in leg 3, the flux in leg 1 must also be reversed and accordingly the magnetizing current delivered by the source 42 must be large enough to magnetize the element 24 about a path enough to effect a reversal about apertures 30 and 34 by means of legs 2 and 3 but notlarge enough to effect a reversal in legs 1* and 3. It has been found that the ratio of these two limits may be varied by varying the diameter of apertures 28 and 32. It has been found also, that a large diameter for these apertures improves the ratio, i.e., it makes it larger, but increases the drive current required form the drive source 46.

It is an important feature of this invention that the normal back flow problem, i.e., transfer of information from right to left during a left-to-right transfer, that exists in conventional magnetic flip-flop circuits is solved by this invention without resorting to either a shunt or a series diode in the transfer circuit. The shunt diode has been eliminated in prior art circuits by proper adjustment of the turns ratio of the windings in the transfer loops be tween the magnetic elements. The novel magnetic element 10 employed herein allows this adjustment to be much less critical than in prior art devices. Thenumher of turns required for output winding 48 is two, while winding 50 is a single turn. This reduction in criticality shouldallow higher switching currents, in this instance denoted or termed priming currents, to be employed with this magnetic arrangement as compared to prior art circuits.

The elimination of the series diode in the transfer loop between magnetic elements is also obviated by this novel magnetic structure. It will be recalled by reviewing FIG.

2 that in the transistion from the one state to the with the bistable circuit 23 will be described wherein two magnetic elements per hit are required.

The structural arrangement of the magnetic elements comprising the shift register 66 is substantially the same as that for the bistable circuit 23. The shift register 66 in this instance comprises a plurality of the multiple state magnetic elements arranged in cascade fashion and identified by the reference character 68, 70, 72 and 74. The input information for the shift register 66 is provided by a write generator 76 connected to the input winding 78 for the magnetic element 68. The input winding 78 is coupled to aperture 80 for magnetic element 68 to control leg 2 thereof as described hereinabove. Similarly, the output winding 82 of the element 68 is coupled to the element 70 by means of its input winding 84. The output winding 86 for element 70 is in turn connected to the input winding 33 for element 72 while the output winding 90 thereof is connected to the input winding 92 for the element 74. Each of these transfer circuits are shown in PEG. 6 as including a series resistor proportioned to reduce the time constants of the transfer circuits as previously mentioned. The prime windings for the elements 63 through 74 are connected up in groups of two sponse to a two beat pattern. The prime windings for the elements 68 through 74 are identified by the reference characters 94, 96, 93 and 100, respectively. The prime windings 94 and 98 are connected in series circuit relationship with the priming source 102 for energization during the same interval While the windings 96 and 100 are also connected in series circuit relationship to be energized from the prime source 102 during a different interval. The drive windings for the magnetic elements 68 through 74 are also similarly arranged with a source 104 in groups of two. The winding 106 is connected in series circuit relationship with the winding 108 while the winding 110 is connected in series circuit relationship with the winding 112 to be energized at a different interval from the aforementioned drive windings.

Table Leg Time Function Zero state.

Transfer In coercive force (11). One state.

Prime coercive force.

Primed state.

Drive coercive force.

Zero state.

The sequence of operation of the magnetic shift register 66 will be described in conjunction with the above table. Assuming that all of the magnetic elements 68 through 74 are in the zero state initially or at time zero, at time 11 in accordance with the above table the write generator 76 energizes the input winding '78 to produce a coercive force in leg 2 of the element 68 so as to estab lish the element in its one state. It will be recalled from the above description that the input winding 78 solely controls leg 2 and accordingly no change in flux occurs in leg 3 and correspondingly no signal is transferred into the element 70. During the next time interval, namely, t3, the paired prime windings for the cores 68 and 72 are energized from the source 102. Since the magnetic element 68 is the only element that is in the one state, it will be the only element to respond to assume the prime state at time t4. At time t5, the drive windings for the cores 68 and 72 are energized together to produce the coercive forces shown in the above table. Following the energization of the drive windings 106 and 108, the binary one that was stored in the magnetic element 68 will be found stored in the element 79. It will be seen that time t5 for the element 68 corresponds to time 11 for the succeeding element, the element '70. At this time, the alternate cycle of pulsing time begins to pulse the second pair of elements 70 and 74 during time intervals. 26 through 1.10 which will correspond respectively with the function set out for 21-15.

In the second cycle of operation, at time 27 (t3) the magnetic shift register 66 will store the binary information 0100 reading from left to right. At time Z7 (13) in this cycle the prime windings 96 and 100 are energized to place the element 70 in its prime state. The magnetic pattern then will read O-Prime-OO. Similarly, at time t8 (t4) the drive windings 110 and 112 are energized and following which energization the binary one bit is transferred from element 70 to element '72 and the cycle will now once again repeat with the binary bits being transferred to the element 68 to the element '70 and from the element 72 to the element 74, respectively, in response to the pulsing pattern from the sources 102 and 104. It will be appreciated that during the time intervals that information is being transferred from the elements 70'and 74 that the write generator 76 may also be energized to write in information into the element 68.

Although the novel magnetic shift register 66 has been described as a two element register, it will be readily appreciated that the register 66 may be modified to provide a one element per hit register. This modification is effected by providing a temporary storage device or delay element in the transfer circuits between the magnetic elements. For example, a temporary storage device may be connected in series circuit relationship with the winding 82 and the winding 84 and which storage device should have sutficient storage time to allow the succeeding element, in this instance element 70, to respond to the energization of the drive winding prior to the arrival of the information transferred from the element 68.

Now referring to FIG. 7, a modified magnetic element will be described wherein a bucking Winding is incorporated into the structure making higher switching speeds possible. The bucking winding 115 is essentially a modification of the prime winding 18 shown in FIG. 1 so as to include a portion 115 to magnetically couple legs 1 and 1 along with the portion 1.15 controlling leg 3. More specifically the winding 115 is wound with the portion 115 around legs 1 and 1 and the portion 115 interlaced through the aperture 14 so as to control the leg 3 in the aforementioned manner. The provision of a bucking winding on the magnetic element 10 allows for the usage of higher priming currents to thereby effect shorter priming time while still avoiding the reversal of flux in legs 1 and 1 during this interval. The remaining windings, namely the input winding 16, the drive winding 22, and the transfer-out winding 20 remain the same as described for the basic magnetic element 10.

The function of the bucking winding 115 is such that when the element 10 is in its zero state the Winding 115 will oppose the reversal of flux through legs 1 and 1 to thereby make overpriming to the spurious one condition more difficult. When a one is stored in the element .10 and the prime winding 115 is energized, the coercive force set up in leg l is such as to tend to switch the direction of the flux therein. However, during this same interval the coercive force due to winding portion 115 on leg 3 is also attempting to effect a reversal in leg 2 andwhich reversal should occur prior to any reversal in the leg 1 The relative switching times of these legs will be evident from a consideration of the flux paths for switching legs 1 and 2, the latter being the much shorter path and should require less time. Therefore, upon the switching of the flux in leg 2, no closure path for leg 1* to reverse on will remain, and so leg 1* will be maintained in its original condition.

The magnetic element 10 may also be modified for logical gating operations as exemplified by the logical or circuit shown in FIG. 8 and the logical not circuit of FIG. 9. The consideration of the logical or circuit of FIG. 8 is generally similar to the basic magnetic element 10 of FIG. 1. To modify the element 10 for providing logical or operation, it is only necessary to pro vide additional input windings interlaced through the aperture 14 for the element 10. Merely for the purposes of clarity in illustrating the invention, only a pair of. input windings 16 and 116 are shown in FIG. 8, it being understood any number may be added thereto consistent with physical structure employed.

The general operation of the logical or circuit is such that an input signal applied to either of theinput windings 16 and 116 will set the element 10 into its one state. Upon setting the element into its one. state, the successive energization of prime winding 18 and drive Winding 22 will be effective to gate or transfer out an output signal representative of the one signal in the output winding 20.

A consideration of the logical not circuit of FIG. 9 will now be made. The basic magnetic element. 10 is modified by the inclusion of an extra input winding identified by the reference character 118 to provide not logic. Not logic is employed herein in the conventional sense, that is when an input signal representative of a binary one is delivered to a logical element, the signal read out from this same element is the normal binary 9 zero. This may also be expressed as a not-one signal. Similarly, when a binary zero input signal is delivered to a logical element, the output signal is a not-zero signal or a one'output signal.

The input winding 118 is interlaced through theaperture 14 and magnetically oriented thereon to control the flux in leg 2 but in opposition and equal to the normal coercive force of input winding 16. The additionalinput winding 118 is connected to a one generator 120. The output of theon e generator is adapted to provide an exciting current to the winding 118 to write in a one in the element in the same fashion as the write generator 122 provided for the input winding 16 and substantially simultaneously with the energization of the input winding 16. The resulting not logic from this arrangement should now be evident in view of the fact thatthe sequencing of the magnetic element 10 is not changed for this not circuit. With the delivery of a binary one from both generators 120 and 122 to their respective windings, the coercive forces in leg 2 tend to cancel one another and leave the element 10 in its original state. When the write generator 122 delivers a zero signal, the one signal delivered by the generator 120 at this time is written into the element 10. Therefore, upon the successive energization of the prime winding 18 and the drive winding 22, a one signal is read-out of the output winding 20. The one output signal is the complement of the zero input signal or a not-one signal.

It will now be appreciated that a novel and improved multi-apertured magnetic device capable of use as a control and computing element has been disclosed. The novel magnetic element disclosed is capable of assuming multiple stable states allowing it to perform functions not previously possible with multipath magnetic elements, such as shift register operation. The shift register arrangement does away with unilateral devices and the like while allowing one way flow of information. The elimination of diodes, and the low number of turns results in cheaper constructed units and superior environmental characteristics.

What is claimed is:

l. A bistable circuit comprising first and second magnetic elements, each of said elements having a plurality of apertures therein, a plurality of windings magnetically coupled to said elements, said plurality of windings comprising an input winding magnetically coupled to each of said elements, an output winding magnetically coupled to each of said elements, means for electrically coupling the input winding of said first element to the output winding of said second element and for electrically coupling the input winding of said second element to the output winding of said first element, a drive winding magnetically coupled to each of said elements, a prime winding magnetically coupled to each of said elements, a pair of information insertion windings magnetically coupled to said first element, and an information extraction winding magnetically coupled to said second element. a

2. A bistable circuit comprising first and second magnetic elements, each of said elements having first and second apertures therein, a plurality of windings magnetically coupled to said elements, said plurality of windings comprising a first input winding magnetically coupled through said first aperture of said first element, a second input winding magnetically coupled through said first aperture of said second element, an output winding magnetically coupled through said first aperture of said first element, means for electrically coupling said first input winding to said second output winding and for electrically coupling said second input winding to said first output winding, a drive Winding magnetically coupled through each of said second apertures, a prime winding magnetically coupled through each of said first apertures, a pair of information insertion windings magnetically coupled through said second aperture of said element, and an information extraction winding mag 10 netically coupled through said first aperture of said second element.

3. A circuit having first and secondmodes of operation, said first mode of operation being characterized by a series of relatively large electrical output pulses and said second mode of operation being characterized by a series of relatively small electrical output pulses, said circuit comprising first and second magnetic elements, each of said elements having first and second apertures therein, and each element adapted to assume three distinct magnetic configurations, means for cyclically changing said configurations in predetermined sequence in each element, said means comprising a first input winding magnetically coupled through said first aperture of said first element, a second input winding magnetically coupled through said first aperture of said second element, an output winding magnetically coupled through said first aperture of said first element, an output winding magnetically coupled through said first aperture of said second element, means for electrically coupling said first input winding to said second output Winding and for electrically coupling said second input winding to said first output winding, a drive winding magnetically coupled through each of said second apertures, and a prime winding magnetically coupled through each of said first apertures; means including an additional Winding magnetically coupled through said first aperture of said first element and responsive to a first input signal for initiating said predetermined changes of configurations, means including a further winding magnetically coupled through said first aperture of said first element and responsive to a second input signal for inhibiting the change of configurations, output means magnetically coupled said first aperture of said second element and responsive to changes from said third configuration to the first configuration to yield a relatively large electrical pulse upon the occurrence of such a change and responsive to the inhibited change to yield a relatively small electrical pulse.

,4. A bistable circuit as defined in claim 1 in which the prime windings include a bucking portion magnetically coupled to each of said elements.

5. A bistable circuit as defined in claim 2 in which the prime windings include a bucking portion magnetically coupled through the second aperture of their respective elements.

6. A circuit having first and second modes of operation, said first mode of operation being characterized by a series of relatively large electrical output pulses and said second mode of operation being characterized by a series of relatively small electrical output pulses, said circuit comprising first and second magnetic elements, each of said elements having first and second apertures therein, and each element adapted to assume three distinct magnetic configurations, means for cyclically chang ing said configurations in predetermined sequence in each element, said means comprising a first input winding magnetically coupled through said first aperture of said first element, a second input winding magnetically coupled through said first aperture of said second element, an output winding magnetically coupled through said first aperture of said first element, an output winding magnetically coupled through said first aperture of said second element, means for electrically coupling said first input winding to said second output winding and for electrically coupling said second input winding to said first output winding, a drive winding magnetically coupled through each of said second apertures, and a prime winding magnetically coupled through each of said first apertures; means including an additional winding magnetically coupled to said first element and responsive to a first input signal for initiating said predetermined changes of configurations, means including a further winding magnetically coupled to said first element and responsive to a second input signal for inhibiting the changes of configurations, output means magnetically coupled to said 1 1 second element and responsive to changes from said third configuration to the first configuration to yield a relatively large electrical pulse upon the occurrence of such a change and responsive to the inhibited change to yield a relatively small electrical pulse.

7. A bistable circuit, comprising: first and second magnetic cores, each having a large aperture and a small aperture; each magnetic core having an input core leg between said large and small apertures, an output core leg between said, small aperture and an adjacent edge of the magnetic core, and a drive core leg between said large aperture and an edge of said core; said drive core leg having a minimum cross-sectional area substantially twice that of the minimum cross-sectional areas of each of said input and output core legs; each magnetic core having a drive Winding on said drive core leg for setting the magnetic core in a first magnetic state in which the flux is in the same direction through said input and output core legs, having an input Winding on said input core leg for setting the magnetic core in a second magnetic state in which the flux in said input core leg is in a direction opposite to the flux in said output core leg, having a prime winding on said output core leg for reversing the magnetic.

flux in both of said input and output core legs, and having an output winding on said output core leg responsive to changing flux conditions in said output core leg; circuit means coupling the output Winding of said first magnetic core with the input winding of the second magnetic core; circuit means coupling the output winding of the second magnetic core with the input winding of the first magnetic core; a second input winding on said input core leg of said first magnetic core for setting said first magnetic core in said second magnetic state; signal energy being transferred from said firstcore to said second core by energizing said prime winding of said first magnetic core to switch said first magnetic core to said third magnetic state and thereafter energizing said drive winding of said first magnetic core to switch said first magnetic core to said first magnetic state.

References Cited in the file of this patent UNITED STATES PATENTS Dinowitz -t Nov. 3,-1959 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,046,532 July 24, 1962 Kent D. Broadbent It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

In the drawings, Sheets 1 to 3, line 2, title of invention, for MAGNET DEVICE", each occurrence, read MAGNETIC DEVICE column 5, lines 71 and 72, strike out "to the magnetic element 26"; column 7, line 52, strike out "time"; column 9, line 67, after "element," insert an output winding magnetically coupled through said first aperture of said second element,

-;V column 9, line 74, after "said", second occurrence, insert first column 10, line 33, after "coupled" insert through Signed and sealed this 5th day of February 1963. SE L ttes ERNEST W. SWIDER DAVID L LADD Attesting Officer Commissioner of Patents 

